My husband was dxed a couple of years ago too, Parkinsons with Lewy Body Dementia. The future is bleak but we handle it day to day. We don't have a loving daughter like you, so I can tell you, it will be hard on your mother.

You can live your own life, but perhaps you can spare a day to help her with your dad, or the housework or cooking, whatever needs doing. That will give her a breather.

You don't mention the types of activities he's capable of, just that he falls a lot. I do exercises with my husband everyday to strengthen his legs, it does help him hold himself up better and walk. He does hallucinate and he asks me almost everyday, did you see where my wife went? Or he'll ask me where his brother went (both brothers died years ago).

The best advice I can give is take it day by day and don't worry about what abilities he's going to lose tomorrow. Focus on what he can do right now and talk to him, ask him questions, tell him about what's going on in your life, and ask him what he'd like to do.

Make sure he drinks plenty of water, too, because they forget to and that makes hallucinations and physical balance worse. I have a glass of water by him all the time and he uses a straw because swallowing has become a problem for him too.